Method and apparatus for making container caps



-0ct. 15, 1940. J, VAN BLARCO'M 2,218,102

METHOD APPARATUS FOR MAKING CONTAINER CAPS Filed Oct. 21, 1937 5 Sheets-Sheet 1 Lu 25 g 17 I I INVENTOR.

ATTORNEY.

J. H. VAN BLARCOM METHOD AND APPARATUS FOR MAKING CONTAINER CAPS Oct. 1-5, 1940.

Filed Oct. 21, 1937 3 Sheets-Sheet 2 mug "WW KW m V/ mm A W m Oct. 15, 1940. J.'H. VAN BLARCOM 2,218,102

METHOD AND APPARATUS FOR MAKING CONTAINER GAP Filed Oct. 21, 1937 3 Sheets-Sheet 3 ATTORNEY.

Patented Oct. 15, 1940 PATENT OFFICE METHOD Aim ArrAnA'rus ron MAKING QQNTAINEltCAPS John Hermon Van Blarcom. Brooklyn, N. Y.-, as-

signor to National Seal Corporation, Brooklyn, N. Y., a corporation of New York Application October 21', 1937, Serial No. 110,202 8 Claims. (o1. 153-2) My invention relates particularly to improved methods and apparatus for making single-piece sheet-metal caps. or closures used for sealing the openings in containers, jars, cans or bottles, in

which the cap seals the container orifice when ailixed in sealing position and is locked thereto by screw threads or lugs outside the contourof the nozzle or neck of the container. These screw-threads are preferably formed on the inturned inner shell integral with the cap skirt, and are adapted to engage. suitable threads or lugs on the neck of the container. In container caps of the lug type, the lower edges of the skirt are preferably formed with an inwardly curled l8; bead inside the peripheral zone of the skirt, which bead carries the inturned locking lips or lugs of the cap.

Present commercial requirements for such screw-thread or lug cap closuresformedof a singo gle piece of sheet metal are (1) that the outer depending skirt shall be uniformly cylindrical and also present a smooth exterior surface throughout its entire area to allow for lacquering of the sheet metal without showing any ing5 dentations resulting from the embossing of .the inner screw threads or formation of the lugs; (2) that the lower edge of the skirt be formed with a rounded bead that lies in the same horizontal plane throughout its circumference in mutual 30' parallelism with the top or crown of the cap; (3) that the rounded screw threads be'forn ied on aninner cylindrical shell integral with the cap skirt without any raw edges of the sheet material comprising this inner shell carrying the; a: screw threads projecting anywhere inside the cap, and also without injuring the lacquer coating applied. to' the sheet metal before it is formed into the completed cap; and (4') that in the caps of the 111: type the inturned locking lips inte o gral with the inwardly rolled bead shall possess sufficient rigidity to form a tight seal, yet with enough flexibility in the cap as a whole when in coacting engagement with the container lugs to allowfor inevitable variations in'the glass container nozzles. l

' The principal object of my invention is to provide a simple, effective and economical method and apparatus for the production of container caps either of the screw-thread type or m of the lug type by bending inwardly thelower margin of the, cylindrical skirt throughout its 1 periphery into an inner cylindrical wall or shell spaced from the skirt, having its raw or free edge preferably formed with a folded hem-within the g j contour of this inner. wall.' Thereafter such'novand hence shown;

ell'y produced container cap may have the inner wall V or shell suitably embossed with screw threads in the-ordinary thread rolling machine .or. by other thread forming machines, or'spacedapart portions ofthis inner wall may be bent or 5 pressed into locking lugs supported integrally by the inwardly-curled bead along the rim of the cap skirt.

Further objects of my invention and advanta'ges derived from utilizing my. improved m'eth- 1 ods and apparatus for shaping and making these single-piece caps from-sheet-metal blanks hav-' ing a circular crown and cylindrical skirt will be hereinafter described in which by a single stroke of the curling tool, the cup-shaped blank is shaped along its lower rim with the inturned cylindricalvwall or shell spaced from the skirt.

In the accompanying drawings,

Fig.1 is a vertical sectional view of theapparatus or tool comprising the essential parts of the mechanism for forming the container, cap, such mechanism being mounted on the ramof a -stamping machine or pressscomm'only used for bending or shaping the sheet-metal;

Fig. 2 is a sectional view somewhat similar to Fig. l, but showing the apparatus or tool as arranged in a subsequent operation or stage of the press in forming the cap shell;

Fig. 3 is an elevation of part of the apparatus superposed upon that shown in'Fig. 2; 80

Fig; 4 is an enlarged detail'secti'onal view of the cup-shaped sheet-metal shell showing the curling die in the first curling operation to form- 2. right angledinturned flange on the rim of the cap skirt'to prepare same for the next operation. This view illustrates a standard curling die having a. circular beveled face that is commonly used no detailed construction need be Fig. 5 isan enlarged detail sectional view of the cap shell shown in Fig. 4 about to be engauged by the external and internal curling dies shown in Figs. land 2;'

Fig. 6 isan enlarged detail sectional view of the cap shell showing the right angleflange of the shell shown in Fig. 4, which is bent downwardly substantially by the heel of the in- "ternal curling die as shown in Fig. 1 in the next curling operation; v

l Fig; 7 is. a sectional view on the same scale as Figs. 4-6, but illustrating the internal curling die raised -to permit further inward curling of the lower margin of the skirt in the next curling operation succeeding that shown in Fig. 6 with the folded hem of Fig. 6 starting to follow the projects upwardly through the slot ilin the lift oourseqt the intern a1 curiingdle;-and lever 40 for the die It and is held thereto by ,l'ig. 8 shows the completion of the curling of 1 the washer-ll and collar 42 secured to the shank j the'shell by the descentof the internal and elr-lv 38 by the iriction pin 48. The lever lli is tulternal curling dies at the end of the stroke crumed on the pin secured in the upturned through the downward movement of the ram of bracket it carried by the ram ll (Fig. 2),.and the press. I t J e such lever ll is a,2 to 1 ratio and isactuated by Similar numerals refer to similar parts the return rod ll passing through the hole-"'01 throughoutthe several figures. the leverto which it is held by the nuts 48. Referring to the drawings. showing the suc- As shown in Fig. 3 the return rod it passes. cesslve cm-ling or inward rolling action on the slidably throughthe mounting plate ll 0! the anlower margin of theeap skirt, the'contiiner cap gle bracket ll fastened to the side of'the press iii-initially stampedrrom ineet-metal into a cupinot w rs rod h vi s pi ned thereto shaped blank by any well-known ma hin to .below the plate 4% the stop collar 4|. Coiled comprise the top'orcrown g and depending cya boutthe upper end of the returnrod l is the II lindrical skirtvril with its right-angled iiangel I :heavv sprin the ower end of which rests on along the skirt rim as shown"!!! Fig.5 by the use 8 the plate ll while -the.upper epgLoi the spri of the wstomary cln-ling die I! having the an- 52 bears against the washer-ll adlustably s ured nular beveled face l3, su h gheet metgl may h on the return rod 48 by the nuts '4, "Ihemechadvantageously coated with'lacquer or other simnl m e ei ei e deeclflbed Provided to M l liar materials for decorative am-meg on the flitate-the intlirned curling die I. in timed relation side of the cap g'g well a; on the i r h uhwith the external curling die as illustrated insucfore such blank is initially stamped to form the cesslve ur in oper ti ns. shown in Fi s. 1- cup-shaped closure shown in Fig. 4. The external .curlingdie I! is secured around This Fig. 4 cap is then'brought into 'pomtion in the lower end or the holder 18 as shown in' Figs. 1 l the stamping'machlne orpress-shown in Figs. 1-3 and 2 to'provide a slight clearance so that the with the right-angled flange il oi the cap skirt e thrust W r 31 m y receive the impact of the flmv m' ith the external and internal eurldie 38 when raised irom its Fig. 1 position to that lngdieg of the'pregsag'ghownmngi; shown in Fig. 2. Thelower end Of the die I 80 Referring more particularly to Figs. 14,- th surrounds the internal die it; and has its outer 80 stamping machine or press comprises the'bed-. circulariace II beveled in substantial parallelism 1 plate ll having the h na mt withthe beveled race ll of the dial bushing I1.

ocket is to encloge th c'gp mm g, whi h The innercircular-iacell of the die" is curved plate; It supports. the dial ring I! enclosing th as a circular ggoove shown in Figs. 5-8 to provide dial l1 upwardlypresented j in conjunction with the curved face 21 of the die b l d 1 lg, T t ordi gry- '28 thejcontlnuous conjoint curved groove shown punehpress (not how is m n l ,in Figs. 2, 7 and 8 when the two dies It and I! any suitable (not shown) .to-impart are locked M th B8 p r n unit in the the usual'vertically'reciprocable movement tothe final urling operation on the c p shell." 2 0 ram ll. l J k a My invention in respect to the operational the'u Mounted on the ram II is the curling tool' partsot my apparatus (Figs. 14) will be more shank 2. held theretov by 'the adjusting nut 2i, -iully described by setting forth not only the sucand secured to the shank II by screw bolts 211s ee ive Operatic 0f the WW l8 5 Whole, t m toolvholdgi- :3 thin wh ch is glldably but also the p cular'ei'i'ects or resultspoi such secured the internal curling punch p 'unger 24' operations upon thcc p-l p d cap shell as more 5 having its lower ends in'the form of an tube particularly shown in Figs. 4-8, all .01 which are. ll and externally threaded to carry the internal Pm Q y 1 1 8 8 "I f the curling punch curlingdie! withits lower end formed wlth'the carrving the coactlng inii fl e and the e;- lnw'ardiycut curved,iace 21 ettendingcitcumferternal die ll.

- enflgllyaround t b tt of the die 1. (Figs. 1 In these operations the ,tool is vertically moved aha 2). The bottom ort e die 2th formed with by having secured to the press ram it the tool the hole a through whichmlides a or shank to suitably diusted by the nut ii to the I the clamplng'and ejectormember it that in its ram- I I FlggQlrandZ poglflqn flnnly hgldfthgup grown In released positlcmthe inter'nal curlingdie 2' mim W m (end of m 1. extends below the external curling die BI (Fig.5).

, a ra tned thereto the cylindrical washer ii ,The top on mar in of theskirt II has already that slides withinthetube'li and supports the P 1 ben inwardly 0 to form the right-angled lower end ot-thecoil spring 3I,the uppei"end oi! flange ii. .As' the ram. .descendswith the which bears against the top 81 oi'the plunger thereby supported tool, the elector first con-' tube a m mg Theplungei' g4 ll'gudtacts th cap crown I to nest the cup-shaped w ably) supported in the ring 34 integral with the 1 Shell in pocket II to hold the shell properly curling shank 2| belowwhich is the spring as in position while the tool performs its successive lied about the plunger with thelower oi curling operations on the lower margin otthe e spring II resting onthe washer li carriedby II. The ejector sprin I mpresses to 55 the pl er tube 2l,-while the upper end of the permit the'iurther lowering oi the tool.

." the internal curlingdie as.

spring I bears against the ring 84. The lower As showliin Fig. 5, the heel of the internal 7 end oi: the holder 23 carries the thrust washer ll curling die 28 strikes the right-angled flange ii encircling the tube il as shown-in; Figs. 1 and 2,' r and bends the latter back along the skirt to form which washer is adapted to engage thetop" or the folded hem ll shown in Figs. land 8 with v i 7 top edge I! 01 such hem passing'upwardly into 70 The layer end oithe internaldie lift shank 3| the groove ti formed between the two dies 2| and is interiorly screw-threaded to ;hold"the upper It (Fig. 6). when the folding-oi this hem is screw-threaded end of the plunger 2| which is completed, and before the top Ill reaches the top encircled by the stop washer ll-that'bears on of the groove 6i between the dies 26 and it, the the ring 34- of the shank 2|. The lift shank 38 internal curling die is raised to its closed positernal curling die 25, and from this point to com pletion of the stroke of the tool, the two curling dies 25 and 55 act as a unit to complete the curling of the shell as shown in Fig. 8.

The lever 40 fulcrumed at 44 on the ram I is a 2 to 1 ratio and is actuated by the return.

rod 45 that has the heavy compensating spring 52 to permit further downward movement of the ram l9 when the internal die strikes the thrust washer 31. As shown the spring 52 is of greater strength than the spring and the latter-is compressed thereby. When the internal die 25 strikes the thrust washer 31, the further upward movement of the lift shank 58 is stopped and because-both ends of the lever are fixed at that moment, the return rod must continue to descend and so compress the spring 52 with the further downward movement of. the ram l9.

This downward movement is so-- timed that it actuates the internal die 25 just as the folded he'm as shown in Fig. 6 is completed and before the top edge 55 of this hem reaches the top of the curved groove 5| between the dies 25 and 55 (Fig.. 1). At" this point while the external die 55 continues its downward movement and,

the folded hem 55 continues topass up into the groove 5| between the, dies, the internal die 25 has not only halted its downward movement but has beg-units upward movement twice as fast as its descent because ofthe 2 to 1 ratio'of the lever 40 until the, die 25 engages the thrust washer 31.

Since this upward. movement of the die 25 is faster than the downward movement of the die 55, no obstruction to the top edge 55 of the folded hem 59 is caused by the face 21 of the die 25 as the latter travels from its Fig. 6 to its a Fig. .7 position. .The tool as a whole is now in its Fig. '7 positionwith the .dies 25 and 55 acting as a unit because the internal die 25 is'held in its raised.position by the lever 55 and because the return rod 45 with its compensating spring- 52 permits a further' lowering of the ram IS with attached curling tool. As the ramand tool descend the top of the folded hem 55 continues to flow around the curling radius of the two dies 25 and 55 (Figs. 7 and 8) until. itis positioned and bent as shown in Figs. 2 and 8 at the end of the downward stroke or movement 0 the ram l5.

When the ram l9 and tool begin their'upward return movement, the cap shell as shown in Fig; 2 is firmly held in the nest or pocket l5 by the ejector 30 under pressure of the spring 32 until the dies 25 and 55 leave the completed cap shell and the ejector 55 breaks contact with such shell. when the return rod 45 lifts to .completely release the tension on the spring 52, the

spring 35 returns the internal die 25 to its're-- leased position that is controlled by the plunger stop Washer 59 to complete the cycle, and the tool as a whole is again in raisedposition ready for, the next stroke in curling the skirt margin of the next cap shell.

The cap shell when completed as shown in .Figs. 2 and.8 presents-the cylindrical-wall 52 spaceddrom the skirt Ill-with the folded hem 59 avoiding 'any visible rawedge insidethe cap, and such wall 52 may then be embossedwith inclined screw threads by any suitablev threadrolling machine to form a screw cap, or spaced portions of the-wall may be uncurledtoproduce spaced lugs to engage projections on the neck of the container. g 2

d My invention asshown'anddescribed is not to be limited to the structural details set forth, but relates broadlytoa method and apparatus for producing sheet metal caps in which thelower margin of the 'skirt. is progressively inwardly curled to produce a' uniformly curled head that merges with a cylindrical wall having its raw edge in the form of a folded hem, such wall being spacedfromthe cap skirt, such form of cap as shown in Figs, 2 and 8 being produced from a cup-shaped sheet-metal blank by a single stroke or pressing operation as I have. hereinbefore set forth in detail and illustrated in Figs.

Iclaim asmyinvention: a I I 1. A method of forming a sheet-metal cap from a cup-shaped blank having a flange 'extending inwardly at right angles to .the skirt in a single stroke of a pair of curling dies having coacting annular grooves, which comprises bending the said flange inwardly into a folded hem by the pressure of the dies, and then further bending the folded hem with adjacent portions of the skirt inwardly during a successive movement of the dies to form a cylindrical wall inside the cap and concentrically spaced from the skirt.

2. A method of forming a sheet-metal cap from a cup-shapedblank having a flange extending inwardly aLright angles to the skirt in a single stroke of'a pair of mutually reciprocable curling dies having coacting annular grooves, which' comprises bending the said flange inwardly into a folded hem by the pressure of the dies, and then further bending the folded hem with adjacent portions of the skirt inwardly during a successivemovement of the dies when looked as a unit to form acylindrical wall inside the cap and concentrically spaced from the skirt.

3. An apparatus for forming a sheet-metal cap from a cup-shaped blank having a flange extendcent portions of the skirt to form a smooth inwardly presented cylindrical wall connected by a radially curved portion to the skirt and of less diameter than; and spaced'from, the skirt with .the hem curled drical wall.

within the contour ofthe cylin- 5. An apparatus for forming a sheet-metal cap from a cup-shapedvblank having a flange extending inwardly atright angles to the blank skir comprising a pairof coacting mutually reciproca bledies having means thereon for converting said flange into an -incurled folded hem, and means operative in another position during a successive movement of the dies for curling the portion of the skirt adjacent said hem inwardly and substantially concentrically-with said skirt to form acylindrical wall spaced from the skirt.

6.1! apparatus for forming asheet-metal cap a from a cup-shaped blank having a flange extendin; inwardly 8t 1181 8118188 00, the blank lkirli comprising a pair of coolcting mutually reciprocable dies having means thereon for convert!!! an flange into an in'ciirled folded hem, and means .operative in another position during a iuoe'enive v.

movement of the dies when looked as a unit for curling the portion or the skirt adjacent said hem inwardly and substantially {concentrically with aaidekirttotormacylindricalwallapaeedirom the skirt.

'7. An apparatus for to aaheet-metfl I .irom a cup-shaped biank having a flange extending inwardly at right angles to the blank skirteomprisingapairptcurling dleahavingoo- 3 acting annular grooves, meana ior moving gaid= dies in timed relation for bending the flange ttf iorman incurled folded hem, means tor'moving and locking said dies as a unit with their annular grooves positioned to provide a curling surface of uniform radius, and means tor moving said 2.21am I dielwhen oentportiofl JOHN amnion VAN BLAMOH. 

